Prosecutors says the 69-year-old Illinois billionaire avoided paying more than $5.5 million in taxes by underreporting his income, report the Chicago Sun-Times and the Chicago Tribune. The government is asking the sentencing judge to seriously consider sentencing guidelines that impose a sentence of 46 to 57 months in prison.

“This is a crime committed not out of necessity but greed, as defendant was earning millions of dollars each of the years of his tax evasion scheme,” prosecutors wrote in a court filing on Tuesday.

Warner’s lawyers say in court documents that the businessman had an unhappy childhood in which he helped care for a schizophrenic mother with little help from his father, the Chicago Tribune reported in an earlier story. The court filing also details Warner’s generosity and charitable contributions, and says he had tried to join an IRS tax amnesty program but was rejected.

Warner’s lawyers are seeking probation. Warner has already agreed to pay a $53 million civil penalty and $16 million in back taxes. He is scheduled to be sentenced next week by U.S. District Judge Charles Kocoras.